Engine throttle



J. A. CRAVERO 2,901,919

Sept. 1, 1959 ENGINE THROTTLE a Sheets-Sheeti Filed Sept. '7. 1954 IN VEN TOR. dosep/z a. Crave/'0 27%RNEY:

p 1, 1959 J. A. CRAVERO 2,901,919

ENGINE THROTTLE Filed Sept. 7, 1954 s Sheets-Sheet 2 INVENTOR.

(Joseph G Crave/"0 94L gab w ATTORNE Y.

U 1 I a...

Sept. 1, 1959 J. A. CRAVERO ENGINE THROTTLE Filed Sept. 7, 1954' 5 Sheets-Sheet 3 INVENTOR. Joseph 62. Crave/"0 QT TORNEY.

United States Patent 1 ENGINE THROTTLE Cravero, East Farmingdale, N.Y., assignor to Joseph A.

N.Y., a

Republic Aviation Corporation, Farmingdale, corporation of Delaware This invention relates generally to control mechanisms and more particularly to a lever for the actuation of the throttle valve or fuel control mechanism of an engine and means operably interposed between said lever and said fuel control mechanism for the predetermined, differential operation of the latter.

The present invention contemplates, among other things, a throttle control quadrant or lever having an operating range through an arc of 90 which corresponds to the operating range of the fuel control mechanism, while the control lever per se is, in fact, being moved through incidental angles the sum of which is in excess of 90 Thus the operating lever or quadrant is less sensitive than the fuel control or feed device whereby to give the operator or pilot additional and more minute control over the operation of the latter.

In addition, the instant invention proposes means whereby the more minute control over the operation of the fuel control mechanism may be obtained and held operable only, during desired portions of the overall range of movement of the lever or quadrant. In this way the entire differential movement between the present lever or quadrant and the fuel control mechanism may be employed exclusively in the segment or arc of the 90 overall operation or range where it is most needed and desired.

With the above and other objects in view, as will be apparent, this invention consists in the construction, combination and arrangement of parts all as hereinafter more fully described, claimed and illustrated in the accompanying drawings, wherein:

Fig. 1 is a front elevation of an engine throttle control lever constructed in accordance with the teachings of the present invention to show the path of movement thereof in travelling in an arc subtended by an angle of 90 to and from extreme positions corresponding to the operation of the fuel control device, the lever being disposed in the initial or low-feed position and the associated fixed structure on which it is mounted being represented by phantom lines;

Fig. 2 is a section taken along line 22 of Fig. 1 to show the manner in which the control lever is operatively connected to independent actuating means for separate and distinct operations of the remote fuel control mechanism (not shown);

Fig. 3 is a section taken along line 33 of Fig. 2 to show the relative position of the actuating means for one operation of the fuel control mechanism when the lever is in the initial or low-feed position;

Fig. 4 is a section taken along line 44 of Fig. 2 to show the relative position of the actuating means for a second operation of the fuel control mechanism when the lever is in its initial or low-feed position; and

Fig. 5 is a diagrammatic illustration of the entire fuel control system to show generally the preferred means by which the independent actuating mechanism for the throttle are indirectly interconnected one to the other for the sequential, differential operation thereof in predetermined 2,901,919 Patented Sept. 1, 1959 ice proportion to the operation of the fuel feed mechanism or throttle.

While the present invention may be employed whereever it is desired to change the ratio of operation between the fuel feed or throttle control mechanism of a combustion engine and the actuating lever or throttle quadrant thereof, it finds particular utility in aircraft, especially where combination propeller and turbo engines are employed. The so-called turbo-prop airplane has come into prominence and has been widely employed because of its proven advantages over other types of aircraft. Most important among these are lower fuel consumption and light weight for its comparatively high horse-power as well as employment of the propeller which provides power for quick take-off and climb and which may, at the same time, be employed to aid in quick stops in landing by reversing the pitch of its blades.

At the same time the full value of the foregoing advantages cannot be attained without the solution of certain problems inherent in the practical application of the turbo-prop airplane. One of the problems, the one to which the present invention is directed, arises out of the fact that turbo-prop engines are capable of producing comparatively great horsepower, in many cases up to substantially twice the horsepower of a conventional propeller-driven aircraft. While it is desirous and advantageous to have unlimited horsepower during flight of the aircraft, it has been found that ground operations, i.e., taxiing and all land maneuvers before actually taking ofi and after landing, of such aircraft are virtually impossible to control. The reason for this is that, upon operation of the conventional control lever or throttle quadrant, greater horsepower is delivered by the engine causing the aircraft to literally jump or buck, making land operations erratic and uncontrollable.

In an effort to overcome this as well as other problems the present invention proposes a means whereby the standard control lever or throttle quadrant may be modified to function differently for flight and ground operations of the airplane. In short, the invention proposes means whereby the normal operation of the throttle actuating lever or control quadrant is desensitized for ground operations only. To this end a mechanism is contemplated by which the effective movement of the actuating lever is slowed down, that is, said lever is made to operate over a greater range or are than the corresponding fuel control device which it controls during land or ground operations. Thus if, for example, the effective range of movement or rotation of the control lever or quadrant is 30 for ground operation and 60 for flight operation, by means of the present invention the actual range of movement thereof in the ground regime may be increased to, for example, 50 while its range of movement in the flight regime remains 60. Hence, during all ground operations movement of the control lever or quadrant through a maximum arc of 50 by the pilot effects a corresponding movement of the fuel control or feed mechanism comparable to only 30". Of course, once the aircraft becomes airborne, continued operation of the lever or quadrant directly controls and operates the fuel control or feed mechanism so that the remaining 60 movement of the former results in the equivalent and concurrent movement of the latter.

Referring more particularly now to the drawings, the numeral 10 designates fixed structure forming a part of the airframe and located within the cabin or cockpit, e.g. the control panel or forward wall of said cabin or cockpit. Fixedly secured to the structure 10 in any suitable and well known manner is a hollow case or housing 11in which the operating mechanism of the present device is located. Within this housing 11, and forming a permanent part thereof, a pair of spaced parallelly disposed upright supporting members 12 are located. Each of the members 12 is pierced with a hole adjacent the lower extremity thereof for the passage therethrough of a bolt 13. A nut14 is threadably mounted on the outer end of the bolt 13 outwardly of the member 12 in opposition to the head thereof. I

1 Medially of 'its length bolt 13 is provided with an enlarged peripheral collar or lobe 15 integrally formed thereon. A lever 16 is centrally mounted on and about the collar'15 for free and unrestricted rotation relative to the bolt 13.. To this end a standard needle bearing 17 is employed between the lever 16 and bolt 13. This bearing 17: comprisesfan annular inner ring 18 having a recased central portion on its inner face to receive therein the: eollarlS of the bolt 13 whereby it'i-s held against movement relative to said bolt, an annular outer ring 19 which overlies and is spaced from said inner ring to receive therein a plurality of needle-type bearings, and an outer locking ring 20 at opposed ends of the rings 18 and 19 when assembled to contain them against relative lateral movement.

On either side of the lever 16 is disposed a comparatively small pulley 21 and a larger pulley 22 both of which are operably mounted for free and unrestricted rotation on the bolt 13 bymeans of and through a needle bearing 23 which is identical in every respect to the bearing 17 just described with reference to the lever 16. Two spacers 24 of identical construction are mounted on the bolt 13 one on each side of the lever 16 and interposed between said lever 16 and each of the pulleys 21 and 22. The inner side, i.e. the side adjacent the lever 16, of each of the spacers 2 4 is recessed centrally to form a lip or flange 23' around its peripheral edge whereby the entire portion of bearing 17 which extends beyond the limits oflever 16 is received in and enclosed by the spacers 24.

The bolt 13 also pierces a guide plate 25 which is disposed thereon with its outer wall or face in flush abutment with the inner wall or face of the upright support 12 associated with the head of the bolt 13. This guide plate 25 is immovably secured to the upright support 12 in any conventional manner, such as, for example, by a number of bolts 26. A spacer 27 is interposed between the inner face of guide plate 25 and the outer surface of pulley 21 to insure the free rotation of pulley 21 on and about the bolt 13.

At the opposite or outer end of the bolt 13 is disc plate 28 is provided to retain all the foregoing parts which the bolt 13 pierces against relative movement longitudinally of'said' bolt. To this end the plate 28 is designed to abut the outer surface of the pulley 22 in opposition to the head of the bolt 13; and an intermediate adjusting nut 29 is provided on the bolt 13 outwardly of said plate 28 and inwardly of the associated supporting member 12. Thus when the intermediate nut 29 is tightened or driven home against the plate 28 all the elements, to Wit, pulleys 21 and 22, lever 16 and the several spacers 24 and 27, are locked or secured against longitudinal displacement on the bolt 13. From'the foregoing it is apparent that the bolt 13 is immovably secured to the case 11 and becomes, in effect, an. integral part thereof. At the same time the bolt 13 serves as acommon support for the lever 16 and pulleys 21 and 22, all of which are capable of unrestricted and independent, rotation thereon.

Additionally, the lever 16 is provided with a vertical, elongated slot 30 of predetermined length in which the needle bearing 17 is located whereby to provide limited vert calmovement of said lever relative to the bolt 13. At its outer or upper end lever 16 is further provided a substantially angularly disposed handle 31 by whiehit may be moved both rotatably and vertically relative to bolt 13. Medially of its length and between the slot 30 and the handle 31, the lever 16 is pierced by a A transverse hole for the passage therethrough of a roller arm 32. This roller arm 32 consists of a bar or axle 33 having a laterally projecting flange 34 integrally formed centrally thereon and by which it may be immovably secured to the lever 16, for example, by means of at least two screws or bolts 35. At its opposed extremities the axle 33 is provided with freely rotatable rollers 36 and 37 which may be connected thereto in the conventional and well-known manner to be disposed on opposite sides of the lever 16.

At its other end, that is, the end remote from its handle, the lever 16 is provided with a transverse aperture for the passage therethrough of the shank 38 of a second roller arm 39. This roller arm 39 terminates at one end in an integral head 40 the inner face of which is designed to abut the side of the lever 16 adjacent the pulley 22 and is immovably secured to the lever 16, for example, by means of at least two screws or bolts 41. A freely rotatable roller 42 is mounted on the other or outer end of the roller arm 39 in the conventional manner and similar in all respects to the rollers 36 and 37.

The overall length of the roller arm 32v is such that when it is operatively connected, as above described, to the lever 16 the roller 36 at one end thereof lies in the plane of the guide plate 25 and the roller 37 atits other end lies in a plane parallel to, but short of, the plane of pulley 22. The roller 42 of roller arm 39 similarly lies in a plane parallel to, but short of, that of the pulley 21.

In order that the lever 16 may be operatively connected to either of the pulleys 21 or 22 as desired, radial extension plates 43 and 44 respectively are provided at and along a portion of the peripheries of the pulleys 21 and 22. Each plate 43 and 44 is in the form of a sector extending outwardly as an integral part of its respective pulley 21 or 22 and so projects from the inner side thereof that its outer surface is contiguously associated with the outer surface of the lever 16. These extensions 43 and 44 project outwardly beyond the rollers 42 and 37 respectively carried by the lever 16 but each contains a cut out or slot 45 and 46 respectively therein to receive the associated roller. Both of these slots 45 and 46 are arcuate in shape and of a width substantially equal to the diameter of the rollers 37 and 42 to the end that they will form cam surfaces over which the, rollers may readily operate when the lever 16 is rotated on and about the bolt 13.

Since the rollers 37 and 42 are disposed on opposite sides of the pivot or bolt 13, the extension plates 43 and 44 are diametrically opposed when the lever 16 is in the initial position, as seen in Fig. 1. The arcuate slot 45 in extension 43 is of a length corresponding to substantially 40 rotation of the lever 16 and terminates at its lower end (Fig. 4)- in a horizontal continuation 47 extending in a direction inwardly of the extension plate 43. The armate slot 46 in extension 44 on the. other hand is of a length corresponding to substantially 20 rotation of the lever 16 and terminates at its upper end. (Fig. 3) in a vertical, continuation 48 extending in a direction inwardly of the extension plate 44.

The cam surfaces formed by the slotsv 45 and 46 and their respective continuations 47 and48 are so organized and arranged with respect to one another and with the rollers 37 and 42 that when the lever 16 is moved out of its initial position (Fig. 1), roller 42 drives or pushes the smaller pulley 21 to which it is operatively connected. Simultaneously. roller 37 moves ineifectually in its coacting slot 46. As movement of the lever 16 is continued, the extension plate 43 is rotated about the bolt 13 until such time as roller 37 reaches theend'of slot 46,'at which time the slot 47 has been moved from the horizontal to the vertical position or into a plane parallel with that of the slot 48.v At this time, since the slot 30 provided in the lever 16 permits vertical movement of said lever relative to the bolt 13, it is 'now possible to lower lever 16. When the lever16 is thus lowered the continued rotation thereof serves to drive or push the extension-plate 44 and its attached pulley 22 while theroller 42 moves inefiectu'ally along in its coacting slot 45 in the extension plate 43 of pulley 21.

In order to further support the lever 16 and to aid in guiding it in its rotation of substantially 90 on and about the bolt 13, the outer edge or top of the semi-circular guide plate 25 is recessed or cut away, as at 49, to create a continuous, arcuate cam surface thereon. This surface consists of an outer or upper cam section 51 having an eifective length corresponding to substantially 50 rotation of the lever 16 and an inner or lower cam section 52 corresponding in length to an arc of 60.

These cams 51 and 52 are organized and arranged to receive the roller 36 carried by the lever 16 and guide it freely during its entire movement which corresponds to the movement of either roller 42 or 37 in arcuate slot 45 or 46. To this end the cam surfaces 51 and 52 are disposed radially about the axis or bolt 13 to correspond in distance and length to the arcuate slots 45 and 46 in the extension plates 43 and 44 and are joined one with the other into one continuous cam surface by an interconnecting slot 53 which is equal in length to the slot continuations 47 and 48 in plates 43 and 44. Moreover, the adjoining ends of the cams 51 and 52 overlap one another a distance corresponding to substantially 20 rotation of the lever 16 with the result that the interconnecting slot 53 is angularly disposed relative thereto. Thus at all times, that is, whether the roller 42 is operatively connected to the pulley 21 through the plate 43 as above described, or whether the roller 37 is operatively connected to the pulley 22 through the plate 44, the roller 36 is constantly engaged in guiding and rolling contact along the outer edge surface of cut out portion 49 of guide plate 25 on either the upper cam surface 51 or lower cam surface 52.

Referring now more particularly to Figs. 3, 4, and 5, the means by which the present control lever is connected to the remote throttle of the airplane will be described. To this end the smaller pulley 21 and the larger pulley 22 is each provided with a cable 54 and 55 respectively which cooperates with the peripheral edge thereof in the usual and conventional manner. Each of these cables 54 and 55 is fixedly secured to its respective pulley 21 and 22 by means of an angular clamping member 56. One face of each of these clamps 56 is disposed in abutment with a face of the associated pulley 21 or 22 to which it is secured by means such as, for example, a plurality of screws 57. At its outer end each clamp 56 terminates in a lateral flange to overlie and be disposed in parallel relationship with the peripheral edge of its respective pulley 21 or 22.

The outer peripheral edge of each pulley adjacent the clamping member 56 is notched or cut out, as at 58, to receive and accommodate therein a ball 59 secured to, so as to be in effect an integral part of, its associated cable 54 or 55. Thus, when the clamping member 56 is operatively connected to its respective pulley 21 or 22, the inner face of the outer angular flange of said member 56 abuts the outer edge of the ball 59 and presses or squeezes it against the base wall of the notch 53 whereby it is secured against all movement relative to the pulley 21 or 22. It may, therefore, be said that cables 54 and 55 are, in effect, an integral part of their respective pulleys 21 and 22 so as to move at all times in unison therewith.

At their opposed ends the pulleys 21 and 22 are similarly connected to a pair of intermediate pulleys 6t) and 61 respectively. Each of these pulleys 60 and 61 is identical in size to the larger pulley 22 and is splined or keyed, as at 62, to a shaft or torque rod 63. At its remote end the shaft 63 is connected to the throttle or fuel control mechanism, generally shown at 64 (Fig. 5), or" the engine of the airplane.

From the foregoing it is apparent that when the control lever 16 is operatively connected to the smaller pulley 21, as hereinabove described, rotation of the lever 16 on and about bolt 13 serves to directly actuate the engine throttle 64 by means of an through the intermediate pulley 60 to which it is directly connected. At the same time the larger pulley 22 is indirectly drivenor rotated about on the bolt 13 by means of and through the intermediate pulley 61 whereby it rolls inefiectively in the slot 46 at a substantially slower rate than the smaller pulley 21. This operation, as above indicated, corresponds to ground operations of the airplane both before take-oif and after landing.

When the lever 16 is lowered, i.e. the connection between said iever 16 and the smaller pulley 21 is disconnected and the connection of lever 16 with the larger pulley 22 is effected, rotation of the lever 16 serves to directly actuate the engine throttle 64 of the airplane by means of and through the intermediate pulley 61. Unlike the previous case, this rotation of pulley 22 serves to operate the engine throttle in direct proportion, since pulley 22 is identical in size to the pulley 61. At the same time rotation of pulley 22 on or about bolt 13 serves to indirectly drive the smaller pulley 21 by means of and through the intermediate pulley 60, however, at a substantially greater rate. This operation of the airplane engine throttle corresponds to flight operations of the airplane.

As above indicated, the movement of the lever 16 while disposed in its upper position, i.e., its position relative to the bolt 13 while the roller 36 is being moved along the upper cam surface 51 of the guide plate 25 corresponds to the regime of operation of the throttle control mechanism during ground operations of the airplane. Also the movement of the lever 16 in its lower position, i.e., its postion during movement of the roller 36 along cam surface 52 corresponds to the regime of operation of the throttle control mechanism when the airplane is in flight. It is, therefore, necessary and desirable to provide some positive means to prevent the accidental and unintentional movement of the lever 16 out of either of these positions once established.

To the above ends a retaining and locking means is provided (Fig. 4). By way of example, this device may consist of a generally rectangular plate 65 permanently secured with one of its faces flush against the surface of the extension plate 43 by a plurality of rivets or bolts 66. One longitudinal edge of the plate 65 aligns and is coextensive with the outer edge of the slot 47, the surface of which is grooved or slotted to receive therein the ends of a spring 67. One end of the spring 67 is secured to one of the bolts 66 and the opposed end is compressed or forced back to contact the shank of the next adjacent bolt 66 on the near side thereof whereby the central portion of the spring 67 is bent outwardly to project inwardly of the slot 47.

Thus, when the control lever 16 has been initially rotated its maximum 50 and the slot 47 has concurrently moved from the horizontal to the vertical position as previously described, the retaining spring 67 serves as a chock against the roller 42 whereby said roller is held in the up position. However, when the lever is aflirmatively lowered or dropped by the intentional act of the pilot, spring 67 is compressed or forced into the side surface of the outer edge of the slot 47 and the roller 42 is allowed to pass over and by it. It this way not only is the lever 16 prevented from accidentally dropping into the flight regime when the aircraft is being moved on the ground, but also the pilot is certain to know if and when the change is effected.

Similarly, when the control lever 16 is located in the down position corresponding to flight operation of the aircraft, it is conceivable that if left unrestricted the lever 16 might unintentionally and accidentally move to its up position, for example, when the aircraft is being rolled or flown upside down. To overcome the possibility of such an occurrence, locking mechanism 68 is employed (Figs. 1 and 2). This locking mechanism comprises a centrally pivotal latch 69 mounted on one side of the lever 16 in association with the handle 31 thereof.. At its upper or outer end the latch 69 is flanged or bent laterally to form a handle 70 therefore. At its op po's'ed end the latch 69 terminates in' an inwardly turned hook 71, which is designed and arranged to be inserted in anopenin 72 provided therefor in the case 11 when the lever 16 is in its downward position whereby it enga es the wall of said case defining the opening 72. A spring 73 is operatively connected, as at 74, to the lever 16 and the handle end of the latch 69 to constantly urge handle upward to rotate the hook 71 outwardly of the lever 16. Thus when the pilot desires to move thelever 16 into its lower position, he first presses down on the handle 70 thereby rotating the hook 71 toward the lever 16 allowing it to pass freely through the opening 72 in the case 11 and then the lever 16 is lowered into the flight regime. When the latch 69 is released at the end of' the downward movement of lever 16, it is forced upward and outward relative to the lever 16 by the action or spring 73 whereby the hook 71 on the end thereof is brought into contact and locking engagement with case 11. In this manner lever 16, once it has been located in the downward position, is locked in this position until such time as the latch 69 is intentionally opened to permit passage of the hook 71 thereon freely through the opening 72.

In order to limit the latch 69 against unnecessary rotation on the lever 16 a stop 74 is provided in operative association with the hook end of the latch 69. This stop 74 consists of a stud or pin 75 which projects laterally from the lever 16 to which it is fixed secured to be received in an arcuated slot 76 provided in the latch 69.

What is claimed is:

1. A control assembly for the operation of the throttle valve of an engine comprising a fixed shaft, a lever mounted on said shaft for free and unrestricted rotation relative thereto, a pair of independent members rotatably mounted on the shaft, each of said members being connected to the throttle valve for movement in unison therewith at a different speed, a pair of interconnected rhenrbers disposed between and operatively connected one to each of the independent members for the transmission of movement from either of said independent members to the other of said independent members, and means operable between the lever and each of the independent members for selectively connecting in the alternative one or the other of said' independent members to the lever for operation of the valve therethrough.

2; A control assembly for the operation of the throttle valve of an engine comprising a fixed shaft, a hand lever mounted for free and unrestricted rotation on said shaft, a pair of independent members rotatably mounted on the shaft one on either side of said lever, each of said members being adapted for rotation at a predetermined, difierent' speed and connected to the throttle valve for the corresponding operation thereof, an interconnecting apparatus operative between the members to transmit proportional movement therebetween, individual means carried bythe lever and inconstant overlapping association with each of the members, and a second means carried by each member and organized and arranged for coaction with the first means whereby one of the members is selectively and operatively connected to the lever and the other member is concurrently disconnected from the lever.

3. A control assemblyfor the operation of the throttle valve of an engine comprising a fixed shaft, a lever operatively mounted on said shaft for free and unrestricted rotation thereon, a pair of independent pulleys rotatably mounted on the shaft and disposed one on either side of said lever, the diameters of said pulleys varying in length one from the other, constantly engaged connection means between each-of the pulleys and the throttle valve, a pair of interconnected pulleys each having a diameter equal to each other and to that of the larger of the independent pulleys disposed between and connected to the independent pulleys for the transmission of movement from either of said independent pulleys to the other of said independent pulleys, and means operablebetween the lever and each of the independent pulleys for selectively connecting only one of said independent pulleys directly to the lever for unitary movement therewith.

4. Acontrol assembly for the operation of the throttle valve of an engine comprising a fixed shaft, a lever mounted on said shaft for free and unrestricted rotation thereon, independent pulleys of different diameters rotatably mounted on the shaft on either side of said lever, interconnecting means operative between the pulleys for the rotation thereof in unison and in the same direction, a direct, constantly engaged connection between each pulley and the throttle valve, and means operable between the lever and each of the pulleys for selectively connecting either one of said pulleys to the lever for unitary movement therewith.

5. A control mechanism for the operation of the throttle valve of an engine comprising a fixed shaft, a lever mounted on said shaft for free and unrestricted rotation thereon, a pair of independent pulleys of different diameters rotatably mounted on the shaft one on either side of said lever, a pair of interconnected pulleys of equal diameter one to the other and to that of the larger of the independent pulleys disposed between the independent pulleys to transmit movement therebetween and to the throttle valve, and means operable between the lever and each of the independent pulleys for selectively connecting one of the independent pulleys to the lever for unitary movement therewith and concurrently disconnecting the other of the independentpulleysfrom the lever. I

6. A mechanism for operation of the engine throttle valve of an airplane comprising a case fixedly secured to the airframe and located within the cockpit of the airplane, a fixed pivot mounted within the case, a pilot controlled actuating lever organized and arranged for free rotation on and about the pivot and disposed in a plane normal to that of the pivot to terminate in a handle projecting outwardly of the case, a pair of independent pulleys disposed one on either side of the lever and mounted for free and unrestricted rotation on the pivot relative to each other and to the lever, a sector plate integrally formed at and along the peripheral edge of each pulley to project outwardly thereof, each of said sector plates being provided with an arcuate slot therein adjacent its outer edge comprising an arc of a circle whose center is common to that of the pivot, a pair of freely rotatable rollers mounted on the lever on each side of the pivot to project at right angles to the lever in opposite directions one to the other and arranged and adapted to be disposed one in each of the slots in the sector plates, means associated with each sector plate and operable by the pilot to lock either one of the rollers against movement in its slot whereby movement of the lever on the pivot serves to move the companion sector plate in unison therewith and concurrently unlock the other roller for the unrestricted movement thereof in its companion slot, and a constantly engaged connection between each of the sector plates and the engine throttle valve to transmit movement of either sector plate to the valve.

7. A mechanism for operation of the engine throttle valve of an airplane comprising a case fixedly secured to the airframe and located within the cockpit of the airplane, a fixed pivot mounted within the case, an actuating lever organized and arranged for free rotation on and about the pivot and disposed in a plane normal to that of the pivot to terminate in a handle projecting outwardly of the case, a pair of sector plates disposed one on either side of the lever and mounted for free and independent rotation on and about the pivot relative to each other and to the lever, each of said sector plates being provided with a slot the defining edges of which being designed to form cam surfaces, a pair of axles fixedly secured to the lever one on each side of the pivot and each located and arranged to project at right angles to the lever in the direction of one of the sector plates so as to be disposed centrally in the slot therein, a roller rotatably mounted on the outer end of each axle adapted to move freely over the cam surfaces aforesaid, means associated with each sector plate to arrest movement of either of the rollers in the slot therein whereby rotation of the lever serves to concurrently rotate the companion sector plate, and a connection interposed between each of the sector plates and the throttle valve to transmit movement of each of the sector plates to the valve.

8. A mechanism for operation of the engine throttle valve of an airplane comprising a case fixedly secured to the airframe and located within the cockpit of the airplane, a fixed pivot mounted within the case, a pilot controlled actuating lever mounted on the pivot for free and unrestricted rotation thereon and disposed in a plane normal to that of the pivot to project outwardly of the case, a pair of independent pulleys disposed one on either side of the lever and mounted for free rotation on and about the pivot relative to each other and to the lever, a pair of interconnected pulleys disposed between the independent pulleys, each of said interconnected pulleys being connected to one of the independent pulleys for the transmission of movement from either of said independent pulleys to the other of said independent pulleys, a direct connection between the interconnected pulleys and the engine throttle valve, a sector plate integrally formed at and along the peripheral edge of each independent pulley to project outwardly thereof, and means operatively disposed between the lever and each of the sector plates and operable by the pilot for the connection of either one of said sector plates to the lever for the movement thereof in unison and the simultaneous disconnection of the other of said sector plates from the lever.

9. A control assembly for the operation of the throttle valve of an engine comprising a fixed shaft, a lever mounted on said shaft for free and unrestricted rotation thereon, guide means to limit and control the path and plane of movement of said lever on and about the shaft, a pair of independent members rotatably mounted on the shaft one on either side of the lever, each of said members being connected to the throttle valve for movement in unison therewith at dilferent speeds, a pair of interconnected members disposed between and connected to the independent members for the transmission of movement from either of said independent members to the other of said independent members, and means operable between the lever and each of the members for selectively and concurrently connecting either one of the members to the lever for unitary rotation therewith and disconnecting the other member therefrom.

10. A mechanism for controlling the operation of a valve comprising a rotary operating lever, two connectors each directly connected to the valve through individual pulley trains having different operating ratios whereby the valve may be adjusted at different speeds, said connectors being disposed in a common vertical plane and different rotary planes, and an engagement carried by the lever and projecting into the vertical plane of the connectors at all times and mounted for vertical adjustment to thereby be disposed in either one of the rotary planes of the connectors aforesaid whereby rotation of the lever directly moves only one of the connectors at a time.

11. A device for controlling the operation of the engine throttle valve of an airplane comprising a single pilots operating lever, a pair of independent members each unconnected from the other and from said lever and connected to the valve through pulley trains having different movement ratios for the adjustment of said valve by said members at dilferent rates, individual and alternate engagement assemblies carried by each member and disposed in the path of movement of the operating lever whereby either one of said members may be operatively connected to the lever to impart movement thereof to the valve, and following means connected between said pulley trains and operative upon actuation of either member for the proportional, diflierential movement of the other member.

12. A mechanism for controlling the operation of the engine throttle valve of an airplane comprising a pilots actuating lever, a pair of unconnected members mounted for independent rotation on a common pivot and each connected to said valve through connectors having different movement ratios for the differential operation of said valve by said members, an engagement individual to each of said members for the operative connection of one of said members to and the simultaneous and concurrent operative disconnection of the other of said members from the lever whereby the connected member alone is moved concurrently with and by the lever, and a follower device connected between the differential connectors for movement with either of the members when operatively connected as aforesaid to concurrently and proportionally move the operatively disconnected member.

References Cited in the file of this patent UNITED STATES PATENTS 690,756 McNutt Jan. 7, 1902 691,968 Paine Jan. 28, 1902 1,017,070 Audri 'Feb. 13, 1912 1,693,451 McCauley Nov. 27, 1928 1,774,738 Vough Sept. 2, 1930 1,827,189 Bruce Oct. 13, 1931 2,406,273 Waite Aug. 20, 1946 2,435,037 Gardiner et al. Jan. 27, 1948 2,544,853 Oates Mar. 13, 1951 

